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Which engine should I use??
Posted: Fri Feb 05, 2010 8:43 pm
by linearaudio
OK- having decided that she isburning oil (and rattling!), I have been trawling the local yard.
They have a 1098 Midget on an "H" plate there, probably needing a rebuild, which sounds a bit of a sought after beast (2" mains?), but the proprietor is trying to steer me towards dumping a going 1275 Maestro lump in instead (he has 3 to shift!). Front and backplate swap, redrill a 1098 flywheel and mate to the existing box. Does that sound practical? Ultimately I would be thinking of re-instating the 1275 flywheel and fitting the overdrive box, so the 1098 flywheel bit would be an interim thing.
Also...... what ratio diff will the Midget have? At present I am running 4.55:1 which, with my habit of cruising at 70-80 has no doubt speeded up the demise of the present lump! I must fit a more suitable ratio when I swap engines!
I have a choice of two Wolseleys to rob for diffs, but they are in the BIG weeds whereas the Midget is out in the open!
Re: Which engine should I use??
Posted: Fri Feb 05, 2010 9:16 pm
by bmcecosse
The Midget diff will be 3.9 I think - big improvement on 4.55. You would need a 1500 Midget to get a 3.7 diff. (Edited! I had the diffs wrong way round =Doh!) Not sure if only the Riley 1.5 had the 3.7 diff - maybe the Wolseleys. If the price is right (offer £30 each - be prepared to go to £40!) - I would take them ALL. Wolseleys will yield useful half shafts too - the Midget ones are shorter! Not so easy to fit a Maestro engine - the crank tail seems to stick out further - I looked at doing this - and sold the engine on. It was however missing it's rear seal - which very much influenced my thoughts. Pity - because it was a 'brand new' engine - having been only used in a Tech Colige for neds to take apart and rebuild - which would explain why the caps were all mixed up - and some on wrong way round

It' wouldn't turn over! Also explains missing rear seal - which killed it for me.
Re: Which engine should I use??
Posted: Fri Feb 05, 2010 10:34 pm
by mike.perry
The 1275 Midget uses the 3.9 diff and the 1500 uses the 3.9 diff then 3.7 according to the Haynes Bible. 4.55 was used on the 1098 van with a L.C. engine but would be a bit low geared unless you were living in a hilly part of the country
Re: Which engine should I use??
Posted: Fri Feb 05, 2010 10:47 pm
by jonathon
Heres a few pics of the Maestro motor
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Re: Which engine should I use??
Posted: Sat Feb 06, 2010 1:52 pm
by linearaudio
mike.perry wrote:The 1275 Midget uses the 3.9 diff and the 1500 uses the 3.9 diff then 3.7 according to the Haynes Bible. 4.55 was used on the 1098 van with a L.C. engine but would be a bit low geared unless you were living in a hilly part of the country
My Traveller started out as a late 948, has 1098 and ribbed box fitted, but still on the 948 diff(4.55). All info seems to point to a 1970 Midget having a 1275 lump, so I think this one must have had a 1098 transplant (its a "goldseal" engine number). Think I'll have to jack a wheelm up and count turns!
Re: Which engine should I use??
Posted: Sat Feb 06, 2010 2:21 pm
by bmcecosse
Are you sure it's a 1098 - if it's Goldseal ? And - very likely to be a normal Minor engine in that case - and possibly NOT the one with the large mains. But - you won't know till you open it up! Well - actually - you should be able to tell from the size of the sump at the rear main bearing - it would have to be a 1275 type if the engine has large mains.
Re: Which engine should I use??
Posted: Sat Feb 06, 2010 3:22 pm
by linearaudio
bmcecosse wrote:Are you sure it's a 1098 - if it's Goldseal ? And - very likely to be a normal Minor engine in that case - and possibly NOT the one with the large mains. But - you won't know till you open it up! Well - actually - you should be able to tell from the size of the sump at the rear main bearing - it would have to be a 1275 type if the engine has large mains.
All I can see at present is the inspection covers, which were deleted early on in 1275's, and the heater takeoff being parallel to the block, where the 1275 is at an angle. I will whip the rocker cover off and see if its a 202 head, which would point towards a big main bearing engine, would it not? Must say I am getting rather more keen on the Maestro lump, Jonathon has confirmed that mods are needed as the crank tail is longer, presumably to accommodate the oil seal housing, but the adaptor plate will come with the engine. Are there any advantages in going for a big bearing 1098 over a 1275 (fuel economy, etc?) or is the 1275 a win-win transplant?
Re: Which engine should I use??
Posted: Sat Feb 06, 2010 3:24 pm
by mike.perry
Easy to tell a 1275 from a 1098, the 1098 has tappet chest covers, the 1275 does not.
You got your post in first.
The 1275 is a more powerful engine and I would imagine that large bearing 1098s are rather thin on the ground.
Re: Which engine should I use??
Posted: Sat Feb 06, 2010 3:41 pm
by bmcecosse
Does seem like 1098 then! It should have 295 head IF a Spridget engine (small or large mains) - a 202 indicates a normal Minor engine. Interested to hear what 'mods' will allow the Maestro engine to be used! As the tail is longer - there can't be much room for the clutch - and the starter pinion may not clear the flywheel ring gear. Perhaps a special flywheel ? I only gave up because mine was missing the rear seal - and they are not available new. The Maestro owner who bought it from me was delighted - travelled many many miles to pick it up!
Re: Which engine should I use??
Posted: Sat Feb 06, 2010 4:45 pm
by jonathon
Only machining of the backplate, alloy breather plate and a bespoke flywheel is needed. The latter for A series box or Ford type 9.